Ocular haemodynamics and colour contrast sensitivity in patients with type 1 diabetes (original) (raw)
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Retinal haemodynamics in individuals with well-controlled type 1 diabetes
Diabetologia, 2008
Aims/hypothesis Abnormalities in retinal haemodynamics have been reported in patients with type 1 diabetes in advance of clinical retinopathy. These abnormalities could therefore be useful as early markers or surrogate endpoints for studying the microangiopathy. Since the DCCT, the increased focus on good glycaemic control is changing the natural history of diabetic retinopathy. Based on this, the aim of this study was to investigate whether patients with type 1 diabetes treated entirely or mostly in the post-DCCT era and tested in the absence of confounding factors show retinal haemodynamic abnormalities. Methods We measured retinal haemodynamics by laser Doppler flowmetry in 33 type 1 diabetic individuals with no or minimal retinopathy (age 30±7 years, duration of diabetes 8.8±4.6 years, 9% showing microaneurysms), and 31 age-and sex-matched non-diabetic controls. The study Diabetologia (
Investigative ophthalmology & visual science, 1996
The authors investigated retinal blood flow changes in patients with insulin-dependent diabetes mellitus (IDDM) and no diabetic retinopathy compared to age-matched subjects without diabetes. They also investigated whether blood glucose levels could modulate retinal blood flow in these patients with diabetes and whether this modulation would impact retinal blood flow data used in cross-sectional studies assessing changes in retinal blood flow. Retinal blood flow was measured using video fluorescein angiography, and blood glucose levels were manipulated using glucose clamp methodologies with continuous basal insulin replacement. Blood glucose levels were clamped at 100, 200, and 300 mg/dl. Retinal blood flow measurements were performed at each blood glucose level after subjects had been stabilized for an hour at each of the different blood glucose levels. Retinal blood flow was found to be significantly decreased (P< 0.01) in the group of patients with no diabetic retinopathy (19.4...
Can pulsatile ocular blood flow distinguish between patients with and without diabetic retinopathy?
Clinical and Experimental Optometry, 2007
Our aim was to determine if pulsatile ocular blood flow (POBF) measurements could distinguish between type 2 diabetes mellitus (DM) subjects with and without diabetic retinopathy (DR). Methods: Ninety-eight DM subjects were recruited. POBF was measured using an Ocular Blood Flow tonometer and retinopathy was assessed using retinal digital photography. The duration of diabetes, blood pressure, glycosylated haemoglobin and plasma glucose level were also recorded. Results: Seventy-two subjects had no DR and 26 subjects exhibited mild to moderate non-proliferative DR. POBF was higher in those subjects with non-proliferative DR but did not reach significance. Those subjects receiving insulin treatment had a significantly longer duration of DM, higher HbA1c and plasma glucose levels and greater incidence of non-proliferative DR compared to subjects receiving oral hypoglycaemic agents, who in turn demonstrated higher levels of these parameters than those who were controlled by diet alone (ANOVA p < 0.05 in all cases). POBF was found to increase with level of management but not significantly so. Conclusions: A single measurement of POBF does not distinguish between subjects with and without mild/moderate non-proliferative DR.
Graefe's Archive for Clinical and Experimental Ophthalmology, 2003
Background: To identify alterations of retinal capillary blood flow in the papillomacular area in preclinical diabetic retinopathy using the Heidelberg scanning laser Doppler flowmeter. Methods: Ten eyes from ten patients with type 2 diabetes and no lesions visible on fundus photography (level 10 of Wisconsin grading) and ten eyes from ten healthy subjects of similar age range were examined with the HRF. Intravisit reproducibility of retinal capillary blood flow measurements was assessed in normal subjects and in type 2 diabetic patients, comparing different measurement areas and different analysis procedures: (a) 10×10 pixel box with original software, (b) 10×10 pixel box with SLDF software, and (c) whole-scan analysis with SLDF software (automatic full-field perfusion image analysis). Results: Intravisit reproducibility for the whole-scan analysis in the papillomacular area was 3.52%, 4.81% and 4.60% for volume (VOL), flow (FLW) and velocity (VEL) respectively. Using this method, mean and SD values for retinal capillary blood-flow are 13.25±2.87, 214.58±55.30 and 0.74±0.17, for VOL, FLW and VEL for healthy eyes, comparing with 19.85±6.22, 360.87±158.70 and 1.20±0.48 in eyes with preclinical diabetic retinopathy (P<0.010, P<0.019 and P<0.015 respectively). Conclusions: The HRF shows acceptable reproducibility when using whole-scan analysis in the papillomacular area. Retinal capillary blood VOL, FLW and VEL were particularly increased in five of the ten diabetic eyes examined, with values over the mean + 2SD of the control population, suggesting that eyes showing increased retinal capillary blood flow may indicate risk of progression.
Retinal hemodynamics in proliferative diabetic retinopathy. A laser Doppler velocimetry study
Investigative ophthalmology & visual science, 1993
This study investigated retinal hemodynamic changes associated with different pathologic features observed on fundus color and fluorescein angiography in patients with proliferative diabetic retinopathy. Retinal circulatory characteristics were investigated in 25 eyes of 23 diabetic patients with proliferative retinopathy using a combination of bidirectional laser Doppler velocimetry and monochromatic fundus photography. Eyes with severe capillary nonperfusion had 32% less average volumetric blood flow rate (Q) than eyes with less severe nonperfusion (P = 0.0005). In addition, eyes with severe vessel staining with fluorescein had 20% less average Q than eyes without staining (P = 0.0508). Eyes with severe fluorescein leakage in the macula had a 17% larger total venous cross-section than eyes with milder leakage (P = 0.027). Eyes with clinically significant macular edema had 11% larger average venous diameter than eyes without this feature (P = 0.0085). Severe capillary nonperfusion ...
Retinal circulatory abnormalities in type 1 diabetes
Investigative ophthalmology & visual science, 1994
To quantify retinal circulatory abnormalities in patients with type 1 diabetes; to 1 diabetes; to compare blood speed and blood flow in major temporal retinal arteries as well as total retinal arterial cross-section measured in patients to that measured in controls without diabetes; to determine which factors are related to the measured abnormalities within the patient group. The laser Doppler technique and monochromatic fundus photography were used to measure retinal circulatory parameters in 39 patients with type 1 diabetes with duration of diabetes between 7 and 20 years and 13 age-matched controls without diabetes. Blood pressure, intraocular pressure, and heart rate were measured in all subjects. Glycosylated hemoglobin was measured in the patients. Retinopathy was assessed using standardized color fundus photography and fluorescein angiography. Total retinal arterial cross-section was, on average, 17% higher (P = 0.007) in the patients than in the controls, and it increased wi...
Choroidal blood flow in diabetic retinopathy
Experimental eye …
The ocular hemodynamics in diabetic patients with increasingly severe retinopathy have been evaluated using a non-invasive computerized methodology. In a group of 19 healthy volunteers the mean ophthalmic arterial pressure and the ocular pulsatile blood flow were 83 +/- 2.4 ...
Pulsatile ocular blood flow in untreated diabetic retinopathy
Acta Ophthalmologica Scandinavica, 2009
Purpose: To measure the pulsatile component of total ocular blood flow in patients with untreated diabetic retinopathy.Subjects and Methods: An adapted pneumotonometer attached to a slit-lamp biomicroscope. 82 age-matched subjects divided into 4 groups: non-diabetic controls (n = 22); diabetics with no clinical retinopathy (n = 20); background diabetic retinopathy (n = 20); pre-proliferative/proliferative diabetic retinopathy (n = 20).Results: The mean pulsatile ocular blood flow values were found to be increased in all grades of diabetic retinopathy (no retinopathy 818 μl/min, background 1015 μl/min, pre-proliferative/proliferative 1097 μl/min) compared to the control group (644 μl/min). These pulsatile ocular blood flow values were significantly higher (p<0.05) in the background and pre-proliferative/proliferate retinopathy groups compared to controls. Pulse volume and pulse amplitude were also higher in the diabetic subjects. Mean arterial blood pressure did not differ across the groups studied.Conclusion: Pulsatile ocular blood flow was found to be higher in diabetics compared to controls and appears to increase as the severity of retinopathy progresses. Such a hyperdynamic circulation may contribute to the pathogenesis of diabetic eye disease.
Retinal haemodynamics in patients with early diabetes mellitus
British Journal of Ophthalmology, 1996
AimsIBackground-The retinal circulation was investigated in a group of 19 patients with insulin dependent diabetes mellitus with less than 4 years of disease duration and no evidence of diabetic retinopathy. Results ofthese patients were compared with those of 16 age-matched normal controls. Methods-Venous diameter (D) was measured from monochromatic fundus photographs. Maximum erythrocyte